Chemical modification of polymeric materials containing chlorine atoms are numerous and well known. The best known chlorine containing polymer is polyvinylchloride. The usual approach of modification of this polymer is by means of grafting onto the macromolecules of various other reactive monomers, or telomers, or other entities, by chemical, photochemical or radiation induced reactions. Recently, Kennedy has developed a general method for the chemical grafting of certain monomers to PVC, using an alkyl aluminum catalyst (Cationic Graft Copolymerization, Ed. J. P. Kennedy, Interscience, 1977).
The methods mentioned above lack practicality because an expensive and dangerous catalyst is used. In addition, to effect a grafting reaction on PVC in accordance with the various methods described in the literature, the PVC has to be dissolved in an organic anhydrous solvent, such as cyclohexanone, or tetrahydrofuran, forming very viscous solutions even at quite low concentrations, which are extremely difficult to handle in a chemical process. This is the main reason why previous attempts to modify PVC by grafting reactions remain to date a laboratory exercise only.
A well known drawback of commercial PVC compositions is their hydrophobic nature. This results in the accumulation of static electricity, and the easy deposition of dust, which in certain application (music records, greenhouse coverings, textile fibers) is very deleterious. Another well known drawback of commercial PVC is its degradation while exposed to the combined action of sunlight, oxygen of air, humidity, and acidic pollutants. This leads to a substantial modification of the aspect (color, gloss) as well as of the mechanical properties (hardness, elasticity, impact resistance) of the irradiated material.